In order to achieve power savings, a known image-reading device, for example, a scanner, is configured to enter a power saving mode to reduce power consumed by reading components used for document reading while the scanner is not in an operating condition.
A known scanner, as an example of an image-reading device that controls power, includes a retractable document mount that is capable of opening and closing with respect to a main body of the known scanner. The known scanner is configured to turn itself on or off in accordance with the opening or closing of the document mount.